A look at the often-cruel realm of fourth grade. Nate and his new friend, Donald, are happy they will be in the same class, but unhappy to find that so is Louisa, a girl who lives to ridicule others. On the very first day, she dubs Donald “King of the Kooties,” and takes every opportunity to taunt and humiliate him. Shy, quiet Donald has no idea how to respond, so Nate devises a plan to get Louisa off their backs. Nate’s solution, to embrace the Kooties title and to publicly include Louisa in it, is clever, but many readers will find it implausible, given Louisa’s well-established spite, aggression, and determination. As a story that takes a look at one approach to the age-old problem of bullies, it works well, straining credibility but never becoming didactic. (b&w illustrations) (Fiction. 7-10)